My son is tall for his age, always has been. So he's a three-year-old kid about the size of a four-year-old. However, the child size S (4-6) runs a bit larger, which I like so I don't have to worry about him growing up too soon. The sleeves of the pants are too long for him and should be taken off. which I don't, so ok.) The material is comfortable and (slightly) breathable (compared to other costumes) but a little light (which is perfect for warm weather, but if you're buying it for a cold Halloween, I'll wear clothes with Long recommend I also bought him Buzz inflatable wings to complete the look but they never last more than the first few minutes after arriving at a party Due to the lightness of the material I hand wash the costume but only because I want to keep the machine from breaking it.I've machine washed it once or twice when it was particularly dirty and it survived the wash but I wouldn't recommend this as a main cleaning method.Overall the kid loves it and I totally justify my money by letting him listen at home when he wants to play, not just once a year on Halloween.